1. Field of the Invention
The present invention relates to a bill identifying apparatus used in an automatic vending machine, money changer, game machine, etc. and a bill identifying method by the identifying apparatus.
2. Description of the Related Art
In a bill identifying apparatus used in an automatic vending machine or the like, a bill inserted through a bill slot is transferred to a bill storage section by transfer means. A sensor section, composed of a magnetic or optical sensor, is provided on a transfer path in the identifying apparatus. Synchronously with the transfer of the bill along the path, the magnetic sensor detects identification data such as a magnetic pattern contained in printing ink on the bill, and/or the optical sensor detects identification data such as a pattern indicative of the quantity of light transmitted through the bill. Based on these identification data, the bill is checked for authenticity and denomination (see Laid-Open Japanese Patent Application Nos. 6-195543 and 7-92853).
Conventionally, sensor components, such as magnetic heads that constitute magnetic sensors, light emitting elements and light receiving elements that constitute optical sensors, etc., are mounted directly on the body of bill identifying apparatuss.
In a bill identifying apparatus built in an automatic vending machine, money changer, or the like, a sensor section must be located on a bill transfer path. Consequently, positions in which magnetic and optical sensors are to be arranged are restricted, so that a bill cannot be measured and identified all through. If the whole area of the bill is expected to be measured, the magnetic and optical sensors has to be increased in number, and circuit components so that identification data detected by the sensors and reference data, such as patterns for reference can be set and stored for each of the sensors, and these data can be compared. This, however, will cause a high manufacturing cost.
If the sensors are reduced in number, measuring spots on the bill for the detection of the identification data will become more limited, and this will make it easier for some evil-minded people who may study the construction of the bill identifying system, especially bill measuring positions for bill identification, to create forged or altered bills that can pass the identifying apparatus without being rejected. Conventionally, to cope with the bills forged or altered with sophisticated cunningness, the identifying accuracy of the identifying apparatus is used to be raised correspondingly. If the identifying accuracy is raised, however, some stained or crumpled authentic bills may possibly be mistaken for counterfeit ones and rejected, producing an adverse effect such as the fall of bill acceptance efficiency.
In these bill identifying apparatuses placed in a severe environment, such as those attached to outdoor vending machines and the like, sensor components for identification suffer a lot of detrimental influences. In general, therefore, identifying apparatuses on vending machines that are located in bad surroundings have shorter lives than those of other vending machines. If the sensor components go wrong, they require maintenance service such that the wrong identifying apparatus is removed from the automatic vending machine for disassembling at a shop or the like, the wrong sensor components are replaced with new ones, and the identifying apparatus has to be reassembled and incorporated into the vending machine.